KVM: x86: report valid microcode update ID

Windows Server 2008 SP2 checked build with smp > 1 BSOD's during
boot due to lack of microcode update:

*** Assertion failed: The system BIOS on this machine does not properly
support the processor.  The system BIOS did not load any microcode update.
A BIOS containing the latest microcode update is needed for system reliability.
(CurrentUpdateRevision != 0)
***   Source File: d:\longhorn\base\hals\update\intelupd\update.c, line 440

Report a non-zero microcode update signature to make it happy.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1fe9637ff15..ea8f9f03e92 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1842,7 +1842,6 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
 
         switch (msr) {
         case MSR_IA32_PLATFORM_ID:
-        case MSR_IA32_UCODE_REV:
         case MSR_IA32_EBL_CR_POWERON:
         case MSR_IA32_DEBUGCTLMSR:
         case MSR_IA32_LASTBRANCHFROMIP:
@@ -1863,6 +1862,9 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
         case MSR_FAM10H_MMIO_CONF_BASE:
                 data = 0;
                 break;
+        case MSR_IA32_UCODE_REV:
+                data = 0x100000000ULL;
+                break;
         case MSR_MTRRcap:
                 data = 0x500 | KVM_NR_VAR_MTRR;
                 break;